The objective of this study was to evaluate the effect of replacing cereals and protein concentrates in a high-cereal concentrate (control) for light lambs with corn distiller’s dried grains with solubles (DDGS; 18%), dried citrus pulp (DCP; 18%), and exhausted olive cake (EOC; 8%) in a byproduct (BYP) concentrate on growth performance, digestibility, ruminal fermentation, and plasma metabolites. Two homogeneous groups of Lacaune lambs (13.8 kg ± 0.25 kg) were fed one of each concentrates and barley straw ad libitum until reaching about 26 kg body weight. There were no differences between groups on feed intake, average daily gain, or feed conversion ratio, but the control diet had greater (p < 0.001) dry matter digestibility. Diet had no effect on post-mortem ruminal pH and total volatile fatty acid concentrations and profile, but NH3-N concentrations were lower (p = 0.003) for the BYP-fed group compared with the control one. However, plasma concentrations of amino acids, total proteins, urea, and hepatic enzymes were not affected by the diet. In conclusion, 44% of feed ingredients in the concentrate for light lambs can be replaced with a mixture of corn DDGS, DCP, and EOC without negatively affecting growing performance and animal health.

The aim of this study was to determine how polyunsaturated fatty acids (PUFA) supplementation can affect the productive and reproductive performance in dairy cows subjected to a fixed-time artificial insemination (TAI) protocol under farm conditions. One hundred and ninety-eight Holstein non-pregnant cows were used. Treatments consisted of a control diet (CON), without added oil, and two diets supplemented with either 2.3% soybean oil (SOY) or 2.3% linseed oil (LIN) as dry matter. The diets were formulated to be isoenergetic and isoproteic. Dry matter intake and milk yield were similar among treatments (p > 0.05). Both the percentage of fat (p = 0.011) and protein (p = 0.022) were higher in milk from animals not fed with oil (CON). The greatest saturated fatty acid (SFA) concentration (p < 0.0001) was observed in milk from cows fed the control diet, without added oil. The monounsaturated fatty acids (MUFA), PUFA, and the n-3 PUFA content was higher (p < 0.0001) in the milk from animals fed with oil with respect to the control treatment. The C18:2 cis-9, trans-11 in the milk of animals fed with oil supplements was significantly higher (p < 0.0001) than in that of the control group. Animals supplemented with linseed oil tended to show higher plasma progesterone level (p = 0.09) and a higher number of pregnant cows on the first artificial insemination (p = 0.07). These animals tended to reduce the number of TAI (p = 0.08). In brief, results showed that vegetable oils rich in PUFA supplementation considerably improve the nutritional profile of milk. PUFA n-3 supplementation slightly improves some reproductive parameters in dairy cows subjected to the fixed-time artificial insemination (TAI) protocol.

Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D' Aquitaine steers (average BW = 293.7 ± 38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 ( P < 0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio ( P < 0.05), OLI had the highest content of t 11-18:1 ( P < 0.01) and c 9,t 11-18:2 ( P < 0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) ( P < 0.001), the highest percentage of PUFA ( P < 0.01) and a lower index of atherogenicity ( P = 0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.

The aim of this study was to assess the effects of replacing 44% of conventional feeds in a high-cereal concentrate (CON) with by-products (BYP concentrate; 18% corn distillers dried grains with solubles, 18% dried citrus pulp, and 8% exhausted olive cake) on the meat characteristics and fatty acid (FA) profile of fattening light lambs. Two groups of 12 Lacaune lambs were fed concentrate and barley straw ad libitum from 13.8 to 26.0 kg of body weight. There were no differences (p ≥ 0.130) between groups in the pH, chemical composition, color, and texture parameters and in the estimated proportions of pigments in the longissimus dorsi. Feeding the BYP concentrate reduced the concentration of thiobarbituric acid reactive substances (TBARS) in the meat after 6 days of refrigerated storage (unmodified atmosphere), probably due to the greater polyphenol content in this concentrate. Compared with CON-fed lambs, the meat and the subcutaneous fat from BYP-fed lambs had lower saturated and greater polyunsaturated FA content as well as greater n-6/n-3 FA. In summary, feeding a blend of corn distiller dried grains with solubles, dried citrus pulp, and exhausted olive cake did not change the composition of the meat but improved its antioxidant status and FA profile.

Fish can go through periods of feed deprivation, either due to natural causes influenced by temperature or management techniques in animal production, affecting their energy metabolism differently, depending on the duration of fasting in days and water temperature. This study showed the effect of different days of fasting before slaughter in rainbow trout by analyzing the intermediary metabolic enzymes in the muscle and liver. For this purpose, a non-fasting group was compared with trout that fasted for 5, 10, and 20 days (55, 107, and 200 degree days (°C d), respectively). A first phase of increased activity of enzymes involved in glycolysis was observed, increasing hexokinase enzyme activity in muscle and pyruvate kinase enzyme activity in muscle and liver. As the fasting days progressed, enzymes involved in the gluconeogenic and glycogenolytic pathways in the liver such as lactate dehydrogenase and glycogen phosphorylase increased their activity regarding the no fasted group. After 20 days of fasting (200 °C d), lipogenic and protein related enzyme activity depletion was observed, leading to significant changes in energy metabolism. Therefore, prolonged fasting with high degree days duration may compromise the energy supply for the vital development of rainbow trout.